In your shoes, what I would really want to know is just how malabsorptive he made it, as that influences both how you supplement in the future, and how you need to eat to lose the weight, as both will likely be somewhat different than with the mainstream procedures like the RNY or DS.
The old purely malabsorptive procedures like the JIB worked fairly well, but had a lot of nutritional complications which is why they were abandoned. The RNY went the other way being primarily restrictive and works well with only moderate nutritional consequences from its mild malabsorption, but weight maintenance is only so-so. The BPD/DS hits something of a sweet spot in being moderately malabsorptive with a similar level of nutritional quirks and a more moderate restriction. The old Scopinaro was more malabsorptive and had more problems than the typical DS (that usually had about a 50cm common channel, compared to 100+ for the BPD/DS).
One of the general rules-of-thumb that we discussed in the DS world is that with the DS, the sleeve (restriction) gets the weight off, while the switch (the malabsorption) keeps it off.
The implication of all of this (from an amateur/non doctor perspective) is that if there is enough malabsorption to effectively take the weight off by itself (a la the old JIB or Scopinaro) then there can be excessive nutritional problems, or if the malabsorption is moderate enough to not cause significant nutritional problems, the weight loss may be marginal. I would assume (hope) that this is the case with what your surgeon did, and that you will have to work harder at the loss part of the equation, but will have typical DS/distal RNY nutritional quirks to work around. This is something that you really need to understand in working with your surgeon in the coming follow up visits.
Good luck!